Challenges with Literature-Derived Data in Machine Learning for Yield Prediction: A Case Study on Pd-Catalyzed Carbonylation Reactions.

The application of machine learning (ML) to predict reaction yields has shown remarkable accuracy when based on high-throughput computational and experimental data. However, the accuracy significantly diminishes when leveraging literature-derived data, highlighting a gap in the predictive capability of the current ML models. This study, focusing on Pd-catalyzed carbonylation reactions, reveals that even with a data set of 2512 reactions, the best-performing model reaches only an of 0.

Oxygen and Electron Storage Effects in W-Modified Ceria Catalysts for Ammonia Conversion.

Tungsten-modified CeO is an excellent catalyst for the catalytic conversion of ammonia. However, the geometric and electronic properties of this catalyst and the detailed reaction mechanisms are not well understood. In this work, the potential configurations of various monomer tungsten oxides supported on the CeO(111) surface (WO(x = 0-4)/CeO(111)) are systematically studied and their relative stabilities are evaluated by using on-site Coulomb interaction corrected density functional theory calculations.

Clarifying the Direct Generation of OH Radicals in Photocatalytic O Reduction: Theoretical Prediction Combined with Experimental Validation.

This work systematically studied thermocatalytic and photocatalytic pathways of formaldehyde degradation and H-assisted O reduction over a Pt/anatase-TiO(101) composite via DFT calculations together with constrained molecular dynamics (MD) simulations. We show that photocatalytic O reduction on Pt/TiO can directly generate OH radicals (*O → *OOH → OH) via two hydrogenation steps with small barriers, and the product selectivity (*HO or OH) is decided by the relative position between catalyst Fermi level and OH/*HO redox potential (theoretical determination of 0.07 V referencing to the SHE).

Surface Reconstruction-Induced Photocatalytic Methanol Reduction Reaction on a Rutile TiO(001) Surface.

Photochemistry of methanol on TiO surfaces is of great importance both fundamentally and industrially. Methanol was previously reported only to occur photogenerated hole-participating oxidation reactions on TiO surfaces. Herein, we report that, upon UV light illumination, the methoxy species formed by methanol dissociation at the 5-fold coordinated Ti sites (CHO(a)) of a reconstructed rutile TiO(001)-(1 × 1) surface also undergoes the C-O bond cleavage into methyl fragments mediated by photogenerated electrons, in addition to the well-established photogenerated hole-participating oxidation reactions.

Can Subsurface Oxygen Species in Oxides Participate in Catalytic Reactions? An O Solid-State Nuclear Magnetic Resonance Study.

The impacts of subsurface species of catalysts on reaction processes are still under debate, largely due to a lack of characterization methods for distinguishing these species from the surface species and the bulk. By using O solid-state nuclear magnetic resonance (NMR) spectroscopy, which can distinguish subsurface oxygen ions in CeO (111) nanorods, we explore the effects of subsurface species of oxides in CO oxidation reactions. The intensities of the O NMR signals due to surface and subsurface oxygen ions decrease after the introduction of CO into CeO nanorods, with a more significant decrease observed for the latter, confirming the participation of subsurface oxygen species.

Construction of Ultrafine PtIr Clusters Supported on CoO Nanoflowers for Enhanced Overall Water Splitting.

Green hydrogen production through electrochemical overall water splitting has suffered from sluggish oxygen evolution reaction (OER) kinetics, inferior conversion efficiency, and high cost. Herein, ultrafine PtIr clusters are synthesized via an electrodeposition method and decorated on the CoO nanoflowers assembled by nanowires (PtIr-CoO). The encouraging performances in electrochemical OER and hydrogen evolution reaction (HER) are achieved over the PtIr-CoO catalyst, with the overpotentials as low as 410 and 237 mV at 100 mA cm, respectively, outperforming the commercial IrO and Pt/C catalysts.

Traces of Potassium Induce Restructuring of the Anatase TiO(001)-(1×4) Surface from a Reactive to an Inert Structure.

Reconstruction of solid surfaces is generally accompanied by changes in surface activities. Here, via a combined experimental and theoretical study, we successfully identified that a trace amount of potassium dopant restructures the mineral anatase TiO(001) single-crystal surface from an added molecule (ADM) termination to an added oxygen (AOM) one without changing the (1×4) periodicity. The anatase TiO(001)-(1×4)-ADM surface terminated with 4-fold coordinated Ti and 2-fold coordinated O sites is (photo)catalytically active, whereas the anatase TiO(001)-(1×4)-AOM surface terminated with O and inaccessible 5-fold coordinated Ti sites is inert.

Dual-functional single-atomic Mo/Fe clusters-decorated CN via three electron-pathway in oxygen reduction reaction for tandemly removing contaminants from water.

Inspired by the development of single-atom catalysts (SACs), the fabrication of multimetallic SACs can be a promising technical approach for the in situ electro-Fenton (EF) process. Herein, dual-functional atomically dispersed Mo-Fe sites embedded in carbon nitride (CN) (i.e.

Contracted Fe-N-C Sites in Single-Atom Catalysts Boosting Catalytic Performance for Oxygen Reduction Reaction.

Promoting the catalyst performance for oxygen reduction reaction (ORR) in energy conversion devices through controlled manipulation of the structure of catalytic active sites has been a major challenge. In this work, we prepared Fe-N-C single-atom catalysts (SACs) with Fe-N active sites and found that the catalytic activity of the catalyst with shrinkable Fe-N-C sites for ORR was significantly improved compared with the catalyst bearing normal Fe-N-C sites. The catalyst C@PVI-(TPC)Fe-800, prepared by pyrolyzing an axial-imidazole-coordinated iron corrole precursor, exhibited positive shifted half-wave potential ( = 0.

Directing Highly -Axis-Oriented ZSM-5 Nanosheets with Pre-estimated Bifunctional Imidazole Cations.

An -topology nanosheet zeolite with a highly -axis-oriented structure has rarely been reported but with a great potential for industrial applications. Theoretical calculations on the interaction energies between the skeleton and ionic liquid molecules indicated the possibility of preferential crystal growth along a specific direction, according to which highly -oriented ZSM-5 nanosheets were synthesized from commercially available 1-(2-hydroxyethyl)-3-methylimidazolium and layered silicate sources. The imidazolium molecules directed the structure formation and meanwhile acted as zeolite growth modifiers to restrict the crystal growth perpendicular to the plane, which induced unique -axis-orientated thin sheets with ∼12 nm thickness.

Strategies to Improve the Oxygen Reduction Reaction Activity on Pt-Bi Bimetallic Catalysts: A Density Functional Theory Study.

Decreasing the level of use of Pt in proton exchange membrane fuel cells is of great research interest both academically and industrially. In this work, we systematically studied the oxygen reduction reaction (ORR) following the four-electron association mechanism at various Pt-Bi surfaces with density functional theory calculations. The results showed that the introduction of Bi changes the potential-determining step of ORR.

Synergistic promotions between CO capture and in-situ conversion on Ni-CaO composite catalyst.

The integrated CO capture and conversion (iCCC) technology has been booming as a promising cost-effective approach for Carbon Neutrality. However, the lack of the long-sought molecular consensus about the synergistic effect between the adsorption and in-situ catalytic reaction hinders its development. Herein, we illustrate the synergistic promotions between CO capture and in-situ conversion through constructing the consecutive high-temperature Calcium-looping and dry reforming of methane processes.

Uncovering Structure-Activity Relationships in Pt/CeO Catalysts for Hydrogen-Borrowing Amination.

The hydrogen-borrowing amination of alcohols is a promising route to produce amines. In this study, experimental parameters involved in the preparation of Pt/CeO catalysts were varied to assess how physicochemical properties influence their performance in such reactions. An amination reaction between cyclopentanol and cyclopentylamine was used as the model reaction for this study.

Acid-catalyzed Disulfide-mediated Reversible Polymerization for Recyclable Dynamic Covalent Materials.

Poly(1,2-dithiolane)s are a family of intrinsically recyclable polymers due to their dynamic covalent disulfide linkages. Despite the common use of thiolate-initiated anionic ring-opening polymerization (ROP) under basic condition, cationic ROP is still not exploited. Here we report that disulfide bond can act as a proton acceptor, being protonated by acids to form sulfonium cations, which can efficiently initiate the ROP of 1,2-dithiolanes and result in high-molecular-weight (over 1000 kDa) poly(disulfide)s.

Unveiling the Surface Structure of ZnO Nanorods and H Activation Mechanisms with O NMR Spectroscopy.

ZnO plays a very important role in many catalytic processes involving H, yet the details on their interactions and H activation mechanism are still missing, owing to the lack of a characterization method that provides resolution at the atomic scale and follows the fate of oxide surface species. Here, we apply O solid-state NMR spectroscopy in combination with DFT calculations to unravel the surface structure of ZnO nanorods and explore the H activation process. We show that six different types of oxygen ions in the surface and subsurface of ZnO can be distinguished.

Surface differences of oxide nanocrystals determined by geometry and exogenously coordinated water molecules.

Determining the different surfaces of oxide nanocrystals is key in developing structure-property relations. In many cases, only surface geometry is considered while ignoring the influence of surroundings, such as ubiquitous water on the surface. Here we apply O solid-state NMR spectroscopy to explore the facet differences of morphology-controlled ceria nanocrystals considering both geometry and water adsorption.

Photoinduced inverse vulcanization.

The inverse vulcanization (IV) of elemental sulfur to generate sulfur-rich functional polymers has attracted much recent attention. However, the harsh reaction conditions required, even with metal catalysts, constrains the range of feasible crosslinkers. We report here a photoinduced IV that enables reaction at ambient temperatures, greatly broadening the scope for both substrates and products.

Isolating Single Sn Atoms in CuO Mesocrystal to Form Ordered Atomic Interfaces: An Effective Strategy for Designing Highly Efficient Mesocrystal Catalysts.

Tuning the electronic structures of mesocrystals at the atomic level is an effective approach to obtaining unprecedented properties. Here, a lattice-confined strategy to obtain isolated single-site Sn atoms in CuO mesocrystals to improve catalytic performance is reported. The Sn/CuO mesocrystal composite (Sn/CuO MC) has ordered Sn-O-Cu atomic interfaces originated from the long-range ordering of the CuO mesocrystal itself.

A unique Co@CoO catalyst for hydrogenolysis of biomass-derived 5-hydroxymethylfurfural to 2,5-dimethylfuran.

The development of precious-metal-free catalysts to promote the sustainable production of fuels and chemicals from biomass remains an important and challenging target. Here, we report the efficient hydrogenolysis of biomass-derived 5-hydroxymethylfurfural to 2,5-dimethylfuran over a unique core-shell structured catalyst, Co@CoO that affords the highest productivity among all catalysts, including noble-metal-based catalysts, reported to date. Surprisingly, we find that the catalytically active sites reside on the shell of CoO with oxygen vacancies rather than the metallic Co.

Achieving Active and Stable Amorphous IrOOH for Water Splitting.

Evaluating the structural and electronic-state characteristics of long-range disordered amorphous iridium (Ir)-based oxides is still unsatisfying. Compared with the benchmark IrO, the higher oxygen evolution reaction (OER) performance brought by IrOOH was normally considered to be associated with the pristine Ir-containing species. However, such a conclusion conflicts with the opinion that high-valence metals can create excellent OER activity.

Unique catalytic mechanisms of methanol dehydrogenation at Pd-doped ceria: A DFT+U study.

Pd-doped ceria is highly active in promoting oxidative dehydrogenation (ODH) reactions and also a model single atom catalyst (SAC). By performing density functional theory calculations corrected by on-site Coulomb interactions, we systematically studied the physicochemical properties of the Pd-doped CeO(111) surface and the catalytic methanol to formaldehyde reaction on the surface. Two different configurations were located for the Pd dopant, and the calculated results showed that doping of Pd will make the surface more active with lower oxygen vacancy formation energies than the pristine CeO(111).

Identification of CO adsorption sites on MgO nanosheets by solid-state nuclear magnetic resonance spectroscopy.

The detailed information on the surface structure and binding sites of oxide nanomaterials is crucial to understand the adsorption and catalytic processes and thus the key to develop better materials for related applications. However, experimental methods to reveal this information remain scarce. Here we show that O solid-state nuclear magnetic resonance (NMR) spectroscopy can be used to identify specific surface sites active for CO adsorption on MgO nanosheets.

Photo-induced hydrophilicity at the ZnO(112̄0) surface: an evolutionary algorithm-aided density functional theory study.

Evolutionary algorithm-aided density functional theory calculations were utilized to determine the stable adsorption structures of HO at ZnO(112̄0) extensively under different coverages. By decomposing the adsorption energetics, we illustrate that HO dissociation to a large extent is actually hampered by the barrier for induced distortion of the ZnO surface, and once the surface becomes less difficult to be distorted it will exhibit higher hydrophilicity or even superhydrophilicity. Specifically, photo-stimulation modelling suggests that the surface Zn-O bonds can be weakened by photo-excitation, and the layer of fully dissociated HO can be then facilitated to form.

Subtle structure matters: boosting surface-directed photoelectron transfer the introduction of specific monovalent oxygen vacancies in TiO.

Oxygen vacancies (O) are widely considered to play crucial roles in photocatalysis, but how and why they contribute to improved performances remains controversial. In this work, we studied the promotional effect of O on photoelectron transfer in TiO, using first-principles density functional theory calculations with correction for on-site Coulomb interactions. We explicitly identified three types of O with different charge states (, charge-neutral , monovalent , divalent O) electronic structure analysis.